Running umbraco 4.7 on ie9. 

I have a client who, at some point, was uploading and publishing pdfs through a certain document type with names that may have been causing problems for the umbraco database. I've read in other posts that if there is a colon as part of the filename it can cause issues.  The issues my client is experiencing are particularly idiosyncratic.

First, the error thrown when "Save and Publish" is clicked is "The Given Path's Format is Not Supported"

Second, this only happens in ie9.  No other ie versions have been attempted on their premises since they're not allowed to run other versions (except through the ie developer tools, where all versions/combinations have been attempted, and all produce the error).  Running ie9 off their premises I am able to upload pdf's without errors.  All other browsers, both on and off their premises, upload pdf's without errors.  Uploading from different users running ie9 on their premises all produce the same error.  Clearing all history/cache does not change the error.

I did go through dbo.umbracoLog and found the first instance of that error being generated, but don't know the filename.  I also don't know why it's happening in such specific circumstances, or what the heck to do to get rid of it.  I'd read you need to delete the offending filename from certain tables, but don't know which ones in this case. 

Any help would be appreciated!